Which of the following represents a typical hydraulic reside

Which of the following represents a typical hydraulic residence time for a flocculation tank?

a)

20 seconds

b)

20 minutes

c)

2.0 hours

d)

2.0 days

Solution

for flocculation tank hydraulic residence time (HRT) = volume of tank/ inflow

so for flocculation tank HRT = 20 minta